Balloon centered radially expanding ablation device

ABSTRACT

A device and associated method for performing ablation procedures on anatomical structures accessible from within the chambers of the heart to form lesions that electrically isolate the tissue.

[0001] This application claims the benefit and priority of U.S.Provisional Patent Application Ser. No. 60/473,774, filed May 27, 2003,which is herein incorporated by reference for all purposes.

BACKGROUND

[0002] 1. Field of the Invention

[0003] The invention generally relates to the treatment ofelectrophysiological disease, and more particularly to devices andmethod for ablating tissue in treating atrial fibrillation.

[0004] 2. Related Art

[0005] A procedure known as the surgical maze procedure has beendeveloped for treating atrial fibrillation, a condition which resultsfrom, disorganized electrical activity in the heart muscle ormyocardium. The surgical maze procedure involves the creation of aseries of surgical incisions in a preselected pattern so as to createconductive corridors of viable tissue bounded by scar tissue.

[0006] Ablative procedures have been used as an alternative to thesurgical incisions used in the maze procedure. Typically, the ablativetechniques include endocardial or epicardial ablation, which createlesions extending through a sufficient thickness of the myocardium toblock electrical conduction.

[0007] Unfortunately, the maze procedure, whether using surgical orablative techniques, is often very time-consuming and can result inlesions which do not completely encircle the pulmonary veins or whichcontain gaps and discontinuities. Most procedures do not include meansfor visualization of endocardial anatomy and most endovascular devicesare often inadequate in relaying the precise position of such devices inthe heart. This may result in misplaced lesions.

SUMMARY

[0008] The present invention provides a device and associated method forperforming ablation procedures on anatomical structures accessible fromwithin the chambers of the heart to form lesions that electricallyisolate the tissue.

[0009] The method includes placing at least one ablation device throughthe major vein or artery usually in the neck or groin area, and guidedinto the heart chambers; deploying an inflatable balloon at an orificewithin the cardiac myocardium in which the balloon can be anchored;radially deploying at least one ablation element; and ablating the heartwall with at least one ablation element to create at least one lesion.

[0010] In another aspect of the invention, an apparatus for forming alesion in the heart wall includes an ablation device including acatheter body concentrically formed with an outer sheath having a distalend and a proximal end; a balloon coupled at the distal end to perform acentering and anchoring function at an orifice within the cardiacmyocardium; at least one ablation element positioned proximal to theballoon which can be radially deployed with respect to the central axisof the apparatus for creating a lesion in the heart wall. The apparatusmay also include a control device at the proximal end for manipulatingthe ablation device.

[0011] The ablation element may be a radiofrequency electrode, microwavetransmitter, cryogenic element, laser, ultrasonic transducer or any ofthe other known types of ablation devices suitable for forming lesions.The apparatus includes a plurality of such ablation devices arrangedalong the working end in a linear pattern suitable for forming acontinuous, uninterrupted lesion around the orifice of heart vasculatureor around the ostium of the pulmonary veins.

[0012] These and other features and advantages of the present inventionwill be more readily apparent from the detailed description of thepreferred embodiments set forth below taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE FIGURES

[0013]FIG. 1A is a simplified side view of an ablation device inaccordance with an embodiment of the present invention;

[0014]FIG. 1B is a simplified sectional view as indicated of a crosssection of the embodiment of FIG. 1A;

[0015]FIG. 1C is a simplified side view of an ablation device shown withalternate ablating member within the sheath in accordance with anembodiment of the present invention.

[0016]FIG. 2 is a side cross sectional view of yet another embodiment ofthe present invention;

[0017]FIGS. 3A and 3B are simplified illustrations of a deployedablation device in accordance with an embodiment of the presentinvention;

[0018]FIG. 4 is a simplified cross sectional view of a balloon inaccordance with an embodiment of the present invention;

[0019]FIG. 5 is a simplified view of an ablation element includingprotective sheath in accordance with an embodiment of the presentinvention;

[0020]FIG. 6 is a simplified view of a deployed ablation device inaccordance with an embodiment of the present invention;

[0021]FIG. 7 is a simplified illustration of a display coupleable to theablation device for showing the radially deployed ablation elements inaccordance with an embodiment of the present invention;

[0022]FIG. 8 is a simplified illustration of an embodiment of thepresent invention.

[0023]FIGS. 9A and 9B are a simplified illustration of an embodiment ofthe present invention.

DETAILED DESCRIPTION

[0024]FIG. 1A and FIG. 1C are simplified side cross-sectional views ofan embodiment of ablation device 100 in accordance with the presentinvention. In this embodiment, ablation device 100 includes a catheterbody 102 having a proximal end 104 and a distal end 106 with a balloon114 formed at distal end 106. Catheter body 102 includes aninflation/deflation lumen 108 surrounded by an outer sheath 111 formedconcentric with lumen 108. In one embodiment, outer sheath 108 can bemade to translate over lumen 108 in a telescopic arrangement.

[0025] Catheter body 102 and balloon 114 of ablation device 100 areconfigured for insertion into a main vein or artery through a smallpercutaneous incision. The extreme proximal end of ablation device 100is operably coupled to a control device (not shown) used formanipulating ablation device 100 from outside the vein or artery. In oneembodiment, ablation device 100 is made to enter the left heart chamberand advanced to the pulmonary veins. Ablation device 100 is madeflexible enough to allow advancement to the heart chambers and can bemade to any suitable dimension to reach the desired location within theheart chamber. Ablation device 100 can be made of a flexiblebiocompatible polymer or polymer matrix with metal wire braids and caninclude radiopaque markers 118 or radiopaque filler such as bismuth orbarium sulfate.

[0026]FIG. 1B is a sectional view as indicated of a cross section ofcatheter body 102 of FIG. 1A. As shown in FIG. 1B, outer sheath 108 caninclude one to a plurality of smaller element housing lumen 116configured to receive an ablation element 110. The one to a plurality ofablation elements 110 are used to form lesions isolating the pulmonaryveins from the surrounding myocardium.

[0027] In one embodiment, each ablation probe 110 disposed in lumens 116includes a pre-shaped wire. In one embodiment, ablation elements 110 mayinclude an energy tip 112 formed at the most distal end of the element.As described in detail below, energy tip 110 may include, for example,an RF electrode or other type of energy source capable of performingablation of tissue. Thermocouples 113 can also be positioned proximateto energy tip 112, or may be welded or bonded to the energy tipsthemselves, to monitor the amount of heat generated at the ablation siteand to facilitate temperature measurement of the target tissue duringablation and thus, prevent overheating. Thermocouples 113 can be coupledto wires which extend to proximal end 104 of ablation device 100 andultimately to temperature monitoring equipment or electrical monitoringequipment as to facilitate mapping of electrical activity at the targetsites.

[0028] As shown in FIG. 2, the pre-shaped wire can be received withinlumens 116 and aligned parallel to a central axis A of catheter body102. Openings 202 are formed along outer sheath 111 to allow ablationelements 110 to exit from lumen 116. In one embodiment, ablationelements 110 exit lumens 116 in a direction toward proximal end 104through openings 202 while in one embodiment, ablation elements 110 canbe made to exit lumens 116 in direction toward distal end 106 as shownin FIG. 1C. As the ablation elements 110 exit lumens 116 the pre-shapedwires radially expand away from central axis A, while at the same timethe pre-shaped wire begins to regain its arcuate shape causing energytip 112 to translate toward distal 106 (FIG. 1A). Generally, asdescribed in greater detail below, the bend in arcuate shaped ablationelement 110 causes energy tip 112 to advance toward the ablation site.

[0029] Ablation elements 110 include electrodes 112 formed at the distalend of ablation elements 110 for delivering current to the myocardium soas to create lesions of sufficient depth to block electrical conduction.Electrodes 112 may be solid metal rings or cylinders, foil strips, wirecoils or other suitable construction for producing elongated lesions. Itis understood that the term electrodes 112 as used herein may refer toany suitable ablating element 112, such as microwave transmitters,cryogenic elements, lasers, heated elements, ultrasound, hot fluid orother types of ablation devices suitable for forming lesions.

[0030] Referring again to FIG. 1B, ablation elements 110 are disposed inouter sheath 111 spaced apart a distance d about the circumference ofsheath 111. The number of ablation elements 110 disposed in outer sheath111 is variable and depends on the desired procedure. In one embodiment,each ablation element 110 is positioned a distance r from the centralaxis A. In one embodiment, ablation elements 110 are positioned so as tofacilitate lesion formation on the three-dimensional topography of themyocardium. Ablation elements 110 can be made of any flexibly resilientmaterial that possess a spring quality and can be pre-shaped, such asNitinol and other memory shape metals, stainless steel, and steelalloys, and the like.

[0031] Proximal end 104 of ablation device 100 further includes acontrol handle (not shown) which locates distal end 106 at one of thepulmonary veins. The control end can includes a handle and one to aplurality of slidable actuators, which are used to extend each ablationelement 110 from lumens 116. An electrical connector suitable forconnection to an energy source can be mounted to the handle.

[0032] As shown in FIG. 2, electrical wires, disposed in electricconduits 204, can be used to electrically couple the energy source toablation elements 110 and ultimately electrodes 112. Each electrode 112can be coupled to a separate wire to allow any electrode 112 orcombination of electrodes to be selectively activated. The thermocouplesmounted near the electrodes can be coupled to temperature or electricalmonitoring equipment to control temperature of selected electrode 112and monitor electrical activity at the target site. Also mounted to thehandle can be a connector for connection to a source of inflation fluidor suction, used for the inflation/deflation of balloon 114.

[0033] In one embodiment, the actuators in the handle are coupled to theproximal end of each ablation element 110, and may be advanced forwardto deploy each ablation element 110 from a non-deployed or retractedorientation, as shown in FIG. 2 to a deployed or radially expandedorientation, as shown in FIG. 1A.

[0034] The ablating element captured within the outer sheath 111 is freeto transverse and rotate relative to the inner sheath 108. This allowsthe positioning of the radially expanded ablating element and itselectrode 112 to vary in distance relative to the location of theanchoring balloon 114 and rotate along the central axis of the anchoredballoon 114. Alternatively, outer sheath 111 and inner lumen 108 arecoupled in a slidable relationship while the ablating element iscaptured in between the outer sheath 111 and inner sheath lumen 108 andnot part of the outer sheath 111. In this alternative embodiment, outersheath 111 can be pulled back relative to inner lumen 108 which causesablation elements to become exposed, which allows ablation elements toradially expand due to their shaped memory and be directed to thetissues to be ablated.

[0035] Referring again to FIGS. 1A and 2, balloon 114 is positioned atthe distal end 106 of ablation device 100 just distal to ablationelements 110. Balloon 114 is used to position and manipulate ablationelements 110. In operation, inner lumen 108 is configured to carry a gasor fluid through opening 120, to or away from balloon 114, to cause theballoon to inflate or deflate as desired. As shown in FIGS. 3A and 3B,the size of the inflated balloon 114 controls the range of the ablationsite along the axis of the vasculature. For example, balloon 114 can beused to anchor ablation device 100 at the opening of the vasculature(FIG. 3A). Alternatively, ablation device 100 can be allowed to enterinto the vasculature and expanded to anchor ablation device 100 upstreamof the vascular opening. In any embodiment, the inflated balloon is usedto position and manipulate the ablation element 110.

[0036]FIG. 1C is a simplified illustration of an alternative embodimentof ablation device 100. In this alternative embodiment, ablationelements 110 are deployed forward toward distal end 106. Upon exitingouter sheath 111, ablation elements 110 take a pre-shaped form whichcauses them to bend around balloon 114 and avoid contact therewith.

[0037] As shown in FIG. 4, in one embodiment, balloon 402 is formed ofmulti-chambers in a shape other than a sphere. Inner lumen 108 caninclude multiple openings 120, to feed gas or liquid into each chamberof balloon 402. For example, balloon 402 can be made with a clove-likeshape. The clover like shaped balloon can anchor ablation device 100within an orifice at the highest points of the clover-like shape, whileallowing blood to flow between the recessed spaces formed between themulti-chamber sections.

[0038] In situations where the ostium is not normal to the axis of thevascular opening, ablation element 110 can be manipulated to contact thehigh and low points of the ostium by the use of balloon 114 havingmulti-chambers and independently controlled inflation chambers. Forexample, filling one of the chambers more or less against the otherchambers can be used to bias ablation elements 110 to only contactspecific quadrants of the circumferential pattern. Alternatively, thebiasing of the elements to specific areas can be accomplished using asingle chamber balloon and independent and selectively deploying theabating element. This may be controlled by the user at the handle.

[0039] The radially expanding ablation elements 110 can be made flexibleenough to account for the varying topography of the opening.

[0040]FIG. 5 is a simplified illustration of ablation element 110including a protective sheath 502 which provides a more efficient energydelivery. Protective sheath 502 can be a non-conductive compliantpolymer. The differential stiffness between the ablation element 110 andthe protective sheath 502 pushes back the sheath relative to the tip ofthe ablation element to form an expanded lip portion or petal 504. Petal504 provides increased impedance and provides minimal heating of bloodsurrounding electrode 112.

[0041] Protective sheath 502 can be made to seal against the tissue wallbefore electrode 112 is energized to minimize the contact with blood andto maximize the contact with the tissue. A soft suction within thesheath 502 can be used to cause the sheath 502 to seal against the softtissue.

[0042] As shown in FIG. 6, petal 504 at the end of sheath 502 can alsoprovide a self-aligning footing for the un-even contours of the tissuewall by directing electrode 112 of ablation element 110 to contact thetissue perpendicular to the surface of the tissue. The flexible ablationelement 110 can adjust to align the petal 504 perpendicular to thecontact surface, since petal 504 will naturally try to bias ablationelement 110 into such an orientation.

[0043] Ablation elements 110 can accomplish focal, segmented, orcircumferential ablation concentric to balloon 114, which is deployed inan orifice of the vasculature, such as the pulmonary vein near itsostium.

[0044] In one embodiment, outer sheath 111 which houses ablationelements 110 is free to rotate with respect to inner lumen 108. Where acircumferential pattern is desired, the radially expanding ablationelements 110 can be indexed while the inner lumen 108 coupled to balloon114 is anchored and remains stationary to complete the ablationconcentric with a central axis of balloon 114.

[0045]FIGS. 9A and 9B show that outer sheath 111 can be made to traversealong the central axis A to provide flexible positioning of ablationelements 110. The traversed position as well as the amount of radialdeployment of ablation element 110 determines the size of thecircumferential pattern and the precise location of the segmented focallesion site (FIG. 8). For example, outer sheath 111 can be positionedsuch that ablation elements 110 deploy to form a circumferential patternC₁ or positioned closer to balloon 114 to form circumferential patternC₂.

[0046]FIG. 7 is a simplified illustration of a display feature 702 toshow when contact has been made between ablation element 110 and thetissue. A visual display can be used with energy delivery equipment toshow when optimum contact has been achieved (impedance). Display 702shows a location of each radially deployed ablation element 110 that hasmade good contact with the target tissue.

[0047] In one embodiment, the LEDs 704 light up a pattern thatcorresponds to the contact points of the ablation elements 110 on thetarget tissue based on an impedance measurement at each electrode 112.Sensitivity setting can be adjusted to show whether the contact made isoptimal or not or how close to optimal the contact has become.

[0048] Having thus described embodiments of the present invention,persons skilled in the art will recognize that changes may be made inform and detail without departing from the spirit and scope of theinvention. Thus the invention is limited only by the following claims.

What is claimed is:
 1. A method comprising: positioning at least oneablation device into the heart chambers; deploying an inflatable balloonat an orifice within the cardiac myocardium in which the balloon can beanchored; radially deploying at least one ablation element; and ablatingthe heart wall with at least one ablation element to create at least onelesion.
 2. An apparatus for forming a lesion in the heart wallcomprising: an ablation device including a catheter body concentricallyformed with an outer sheath having a distal end and a proximal end; aballoon coupled at the distal end to perform a centering and anchoringfunction at an orifice within the cardiac myocardium; and at least oneablation element positioned proximal to the balloon which can beradially deployed with respect to the central axis of the apparatus forcreating a lesion at a lesion creation site in the heart wall.
 3. Theapparatus of claim 2, further comprising an insulative sheath formedaround the ablation element to seal an electrode from contact withsurrounding blood at the lesion creation site, said insulative sheathbeing flared at the tip to orient the electrode normal to the tissuesurface to be ablated for maximum delivery of energy.
 4. The apparatusof claim 2, wherein said outer sheath is configured to translate overthe catheter body in telescopic arrangement to radially deploy at leastone ablation element with respect to the central axis of the catheterbody.
 5. The apparatus of claim 2, wherein said outer sheath can includeone to plurality of smaller housing lumens configured to receive one toplurality of ablation elements.
 6. The apparatus of claim 2, whereinsaid catheter body is coupled to said at least one ablation element andis configured to translate over an inner lumen in telescopic arrangementwhere the inner lumen is coupled to said balloon at its distal end. 7.The apparatus of claim 2, wherein said at least one ablation elementcomprises a radiofrequency electrode, microwave transmitter, cyrogenicelement, laser, ultrasonic transducer or any of the other known type ofablation element suitable for forming lesions.
 8. The apparatus of claim2, wherein said at least one ablation element comprises a pre-shapedwire capable of delivering RF energy at said lesion creation site. 9.The apparatus of claim 8, further comprising at least one thermocouplepositioned proximate to said at least one ablation element to monitorthe amount of heat generated at the lesion creation site and tofacilitate temperature measurement of target tissue at the lesioncreation site.
 10. The apparatus of claim 8, further comprisingconductive leads coupled to said pre-shaped wire, said conductive leadsconfigured to connect to mapping equipment to facilitate mapping of theelectrical activity at said lesion creation site.
 11. The apparatus ofclaim 8, wherein said pre-shaped wire comprises a flexibly resilientmaterial that possess a spring quality.
 12. The apparatus of claim 11,wherein said flexibly resilient material that possess a spring qualityconsists of materials taken from the group of Nitinol, other memoryshape metals, stainless steel, and steel alloys.
 13. The apparatus ofclaim 8, wherein said pre-shaped wire comprises a shape taken form thegroup of solid metal rings or cylinders, foil strips, wire coils andother suitable construction for producing elongated lesions.
 14. Theapparatus of claim 2, wherein said at least one ablation elementcomprises microwave transmitters, cryogenic elements, lasers, heatedelements, ultrasound, hot fluids and other types of ablation elementssuitable for forming lesions.
 15. The apparatus of claim 2, wherein saidat least one ablation element comprises a plurality of spaced apartablation elements positioned about the circumference of the catheterbody and outer sheath.
 16. The apparatus of claim 2, said at least oneablation element comprises a plurality of ablation elements positionedto facilitate lesion formation on the three-dimensional topography ofthe pulmonary vein ostium.
 17. The apparatus of claim 2, wherein said atleast one ablation element is received within the outer sheath alignedparallel to a central axis of the catheter body, said at least oneablation element radially expanded away from the central axis of thecatheter body to allow said at least one ablation element to regain apreformed arcuate shape.
 18. The apparatus of claim 2, furthercomprising a handle which controls the distal end of the catheter bodyto position said distal end, said handle including a slidable actuatorwhich controls the amount of transverse movement of the outer sheathrelative to catheter body containing said at least one ablation elementto control the amount of said at least one ablation element that can beradially deployed.
 19. The apparatus of claim 2, further comprising ahandle including a slidable actuator which can control the radialextension of said at least one ablation element.
 20. The apparatus ofclaim 19, wherein said slidable actuator is configured to selectivelydeploy said at least one ablation element.
 21. The apparatus of claim 2,wherein said at least one ablation element comprises a plurality ofablation elements, wherein leads couple an energy source to each of saidablation elements, wherein each ablation element is wired to allowselective activation of said ablation elements separately or incombination.
 22. The apparatus of claim 2, wherein said outer sheathtransverses and rotates relative to said central axis to allow theinitial positioning of the at least one ablation element to vary indistance relative to the location of the balloon and to rotate along thecentral axis.
 23. The apparatus of claim 2, wherein said balloon is usedto position and manipulate the at least one ablation element.
 24. Theapparatus of claim 2, wherein said balloon is configured to inflate tovariable sizes to control where the balloon is located within theorifice which varies the positioning of the at least one ablationelement.
 25. The apparatus of claim 2, wherein said balloon comprisesmulti-chambers in a shape other than a circular cross-section, whereinthe inflation of said multiple chambers is independently controlled toallow for biasing the at least one ablation element to a specific lesioncreation site.
 26. The apparatus of claim 25, wherein said multi-chamberballoon comprises a clover-like shape wherein the most outer point ofthe multi-chamber balloon positions the ablation device while allowingblood to flow between recessed spaces formed between the multi-chambersections and the heart wall.
 27. The apparatus of claim 2, furthercomprising a visual display feature integrated with energy sourceequipment configured to indicate evidence of contact made between the atlest one ablation elements and the lesion creation site.
 28. Theapparatus of claim 27, wherein said visual display feature comprises anLED pattern corresponding to a contact point between the at least oneablation element and the lesion creation site.
 29. The apparatus ofclaim 27, wherein said visual display feature comprises an adjustablesensitivity setting to indicate a level of contact between the at leastone ablation element and the lesion creation site.
 30. An apparatus forforming a lesion in the heart wall comprising: an ablation deviceincluding a catheter body concentrically formed with an outer sheath andinner lumen having a distal end and a proximal end; a balloon coupled atthe distal end of the inner lumen to position the catheter; and at leastone ablation element positioned proximal to the balloon which can beradially deployed with respect to central axis of the apparatus and canbe indexed while inner lumen remains stationary and can traverse alongthe central axis.
 31. The apparatus of claim 30, wherein said outersheath is configured to translate over the catheter body in telescopicarrangement to radially deploy at least one ablation element withrespect to the central axis of the catheter body.
 32. The apparatus ofclaim 30, wherein said outer sheath can include one to plurality ofsmaller housing lumens configured to receive one to plurality ofablation elements.
 33. The apparatus of claim 30, wherein said catheterbody is coupled to said at least one ablation element and is configuredto translate over an inner lumen in telescopic arrangement where theinner lumen is coupled to said balloon at its distal end.
 34. Theapparatus of claim 30, wherein said at least one ablation elementcomprises a radiofrequency electrode, microwave transmitter, cryogenicelement, laser, ultrasonic transducer or any of the other known type ofablation element suitable for forming lesions.
 35. The apparatus ofclaim 30, wherein said at least one ablation element comprises apre-shaped wire capable of delivering RF energy at said lesion creationsite.
 36. The apparatus of claim 35, further comprising at least onethermocouple positioned proximate to said at least one ablation elementto monitor the amount of heat generated at the lesion creation site andto facilitate temperature measurement of target tissue at the lesioncreation site.
 37. The apparatus of claim 35, further comprisingconductive leads coupled to said pre-shaped wire, said conductive leadsconfigured to connect to mapping equipment to facilitate mapping of theelectrical activity at said lesion creation site.
 38. The apparatus ofclaim 35, wherein said pre-shaped wire comprises a flexibly resilientmaterial that possess a spring quality.
 39. The apparatus of claim 38,wherein said flexibly resilient material that possess a spring qualityconsists of materials taken from the group of Nitinol, other memoryshape metals, stainless steel, and steel alloys.
 40. The apparatus ofclaim 35, wherein said pre-shaped wire comprises a shape taken form thegroup of solid metal rings or cylinders, foil strips, wire coils andother suitable construction for producing elongated lesions.
 41. Theapparatus of claim 30, wherein said at least one ablation elementcomprises microwave transmitters, cryogenic elements, lasers, heatedelements, ultrasound, hot fluids and other types of ablation elementssuitable for forming lesions.
 42. The apparatus of claim 30, whereinsaid at least one ablation element comprises a plurality of spaced apartablation elements positioned about the circumference of the catheterbody and outer sheath.
 43. The apparatus of claim 30, said at least oneablation element comprises a plurality of ablation elements positionedto facilitate lesion formation on the three-dimensional topography ofthe pulmonary vein ostium.
 44. The apparatus of claim 30, wherein saidat least one ablation element is received within the outer sheathaligned parallel to a central axis of the catheter body, said at leastone ablation element radially expanded away from the central axis of thecatheter body to allow said at least one ablation element to regain apreformed arcuate shape.
 45. The apparatus of claim 30, furthercomprising a handle which controls the distal end of the catheter bodyto position said distal end, said handle including a slidable actuatorwhich controls the amount of transverse movement of the outer sheathrelative to catheter body containing said at least one ablation elementto control the amount of said at least one ablation element that can beradially deployed.
 46. The apparatus of claim 30, further comprising ahandle including a slidable actuator which can control the radialextension of said at least one ablation element.
 47. The apparatus ofclaim 46, wherein said slidable actuator is configured to selectivelydeploy said at least one ablation element.
 48. The apparatus of claim30, wherein said at least one ablation element comprises a plurality ofablation elements, wherein leads couple an energy source to each of saidablation elements, wherein each ablation element is wired to allowselective activation of said ablation elements separately or incombination.
 49. The apparatus of claim 30, wherein said outer sheathtransverses and rotates relative to said central axis to allow theinitial positioning of the at least one ablation element to vary indistance relative to the location of the balloon and to rotate along thecentral axis.
 50. The apparatus of claim 30, wherein said balloon isused to position and manipulate the at least one ablation element. 51.The apparatus of claim 30, wherein said balloon is configured to inflateto variable sizes to control where the balloon is located within theorifice which varies the positioning of the at least one ablationelement.
 52. The apparatus of claim 30, wherein said balloon comprisesmulti-chambers in a shape other than a circular cross-section, whereinthe inflation of said multiple chambers is independently controlled toallow for biasing the at least one ablation element to a specific lesioncreation site.
 53. The apparatus of claim 52, wherein said multi-chamberballoon comprises a clover-like shape wherein the most outer point ofthe multi-chamber balloon positions the ablation device while allowingblood to flow between recessed spaces formed between the multi-chambersections and the heart wall.
 54. The apparatus of claim 30, furthercomprising a visual display feature integrated with energy sourceequipment configured to indicate evidence of contact made between the atlest one ablation elements and the lesion creation site.
 55. Theapparatus of claim 54, wherein said visual display feature comprises anLED pattern corresponding to a contact point between the at least oneablation element and the lesion creation site.
 56. The apparatus ofclaim 54, wherein said visual display feature comprises an adjustablesensitivity setting to indicate a level of contact between the at leastone ablation element and the lesion creation site.
 57. A method forcreating a lesion in the heart wall to create an ablation pattern toelectrically isolate the vasculature from the chamber and to create asegmental electrical isolation for treatment of cardiac arrhythmia, themethod comprising: positioning at least one ablation catheter havingproximal and distal portion into the heart chamber near a vasculatureostium; deploying an inflatable balloon to position at least oneexpandable ablation element proximal to the balloon, traversing theouter sheath along the catheter body to expose the at least one ablationelement in a radial direction relative to a central axis of the ablationcatheter; advancing the exposed ablation element along an inner lumen ofthe catheter to cause said at least one ablation element to contact achamber wall about the vasculature ostium; and ablating a lesion patternon said chamber wall to electrically isolate the vasculature ostium. 58.The method of claim 57, wherein said ablating a lesion pattern on saidchamber wall comprises performing focal, segmented, or circumferentialablation.
 59. The method of claim 57, wherein said ablating a lesionpattern on said chamber wall comprises forming a circumferential lesionpattern around the vasculature ostium by repeatedly rotating the atleast one ablation element about the central axis and traversing in andout to contact the chamber wall while activating the ablative energyupon contact.
 60. The method of claim 57, wherein said deploying saidinflatable balloon comprises positioning the inflatable balloon insidethe vasculature ostium.
 61. The method of claim 57, wherein saidvasculature ostium comprises a pulmonary vein, wherein said pulmonaryvein can be a single distinct circular ostium, two distinct circularostia sharing a vascular wall, and one elliptical-shape common ostiumthat bifurcate or trifurcate to separate pulmonary veins.
 62. The methodof claim 61, which can be ablated using the multi-chamber balloon whichcan bias the ablating member to selectively ablate specific quadrants ofcircumferential ablation pattern.
 63. The method of claim 57, whereinsaid advancing the exposed ablation element comprises controlling thelesion pattern shape and size by allowing only a predetermined portionof the at least one ablation element to be exposed and to regain apreselected shape.
 64. The method of claim 57, further comprisingvisually displaying points of contact made between the at least oneablation element and targeted tissue using a feature made of an LEDpattern corresponding to said contact points of the ablation element onthe target tissue, wherein the visual display has an adjustablesensitivity setting to show the levels of contact.
 65. The method ofclaim 64, wherein deploying said inflatable balloon comprises deployinga multi-chamber balloon, wherein said each chamber of said multi-chamberballoon is configured to be independently controlled to increase ordecrease the electrical contact made between target tissue and the atleast one ablation element.
 66. A method for mapping the electricalsignals inside the vasculature and around the ostium on the chamber sideof the heart, the method comprising: positioning a catheter having acatheter body and an outer sheath inside the vasculature or outside thevasculature around the ostium on the chamber side; and radiallyexpanding a predetermined amount of pre-shaped ablating elements toallow each pre-shaped ablating elements to regain a preselected shape bycontrolling the amount of transverse movement of the outer sheathrelative to the catheter body which contains the pre-shaped the ablatingelements.
 67. A method of claim 66, wherein said pre-shaped ablatingelements are coupled with mapping electrodes which contact tissue andprovide mapping signals to a mapping device connected to a proximal endof the catheter.